I have perfectly ordinary standard-pull brake levers on my bike. When the temperature gets below 20F or so, the left-hand one seizes up, not wanting to pull, and not braking well if I force it. Once the temperature warms up a bit, it's fine.

My guess is that there's some gummy old lube in the cable housing.
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Daniel R HicksJan 15 '13 at 0:15

1

If it were water the cable would stop operating once the temp got much below 32, and it would be sort of an on/off thing. Gummy lube could have its threshold at any temp, and would have a more gradual worsening as it got colder.
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Daniel R HicksJan 15 '13 at 4:49

2 Answers
2

If the brakes are reluctant to move in both directions then it's mostly likely water in the lines. You may be able to get away with bringing the bike inside letting it dry out for a day or two and re-sealing the lines with grease.

Could be water freezing inside the housing, but don't forget that the viscosity of any lubricant is going to increase as the temperature decreases so that could be your problem as well. If you do re-lubricate your cable, be sure to use as light of a lube as possible. If that doesn't work, try replacing the cable and housing. If you're running v-brakes, be sure that the little rubber boot is staying seated against the end of the brake noodle.